Every Tool You Need for Documents

How DoctorDocs Tools Work

Browser-First Processing

The majority of DoctorDocs tools run entirely inside your web browser using two technologies: WebAssembly and the Web Canvas API. WebAssembly (WASM) is a low-level binary format that lets complex software — normally written in C++ and run on servers — execute directly inside Chrome, Firefox, Safari, or Edge at near-native speed. This means that when you merge two PDFs, compress an image, or extract text from a handwritten note, those computations happen on your own device. Nothing is sent to a remote server. There are no file-size limits, no queues, and no privacy concerns about sensitive documents being stored on someone else's infrastructure.

OCR: How Handwriting Becomes Text

Optical Character Recognition (OCR) converts images of text — scanned pages, photographs, handwritten notes, and screenshots — into machine-readable characters. Modern OCR engines use LSTM (Long Short-Term Memory) neural networks that learn contextual patterns across entire words and lines, rather than matching individual letter shapes to a fixed template. This contextual awareness is what allows the engine to correctly interpret a blurry prescription, distinguish "rn" from "m", or read a partially obscured word by inferring from surrounding context. DoctorDocs uses a fine-tuned OCR pipeline optimised specifically for medical handwriting — one of the most challenging OCR domains due to unconventional abbreviations, drug names, and non-standard letterforms.

PDF Tools: What Happens Inside Your Browser

PDF processing on DoctorDocs is powered by two open-source libraries compiled to WebAssembly: PDF.js (by Mozilla) for reading and rendering PDF content, and pdf-lib for creating and modifying PDF documents. When you merge two PDFs, pdf-lib reads the cross-reference tables from each file, combines the page trees, deduplicates shared resources (fonts, images), and writes a new PDF binary — all in RAM inside your browser tab. No bytes ever touch a server. The same applies to splitting, rotating, compressing, adding page numbers, watermarking, and form filling. The only exception is OCR on scanned PDFs, where advanced AI models are optionally invoked via our secure API after explicit user consent.

AI Features: Gemini and Secure API Calls

For tasks that exceed what client-side WASM can handle — interpreting blood test panels, summarising long documents, translating complex medical reports, or analysing glyph quality in HandFont Studio — DoctorDocs routes requests through the Google Gemini API via our own backend. The backend never stores document content; data is passed through, processed, and immediately discarded. Requests are authenticated, rate-limited per user, and transmitted over TLS. AI features are clearly labelled on each tool page and require a free DoctorDocs account to prevent abuse and cover the marginal API cost.

Font Creation: From Pen Strokes to Installable Fonts

HandFont Studio is DoctorDocs's most unique tool. It lets you draw your own handwriting on a professional typographic canvas — complete with ascender, cap-height, x-height, baseline, and descender guide lines — and instantly download a real .otf font file that installs in Windows, macOS, Microsoft Word, Adobe Photoshop, Canva, and Figma. Behind the scenes, every stroke is processed through a Catmull-Rom spline algorithm that eliminates mouse jitter and produces smooth curves. A velocity-based pressure simulation varies the stroke width the same way a real ink pen does — thinner on fast strokes, broader on slow deliberate ones. The resulting smooth outlines are converted to OpenType Bézier paths and assembled into a valid font binary entirely in the browser.